High wind warnings remained in effect for much of Southern California Friday morning after powerful gusts knocked out power for tens of thousands of utility customers Thursday, stoked a wildfire in the hills above Los Angeles that damaged expensive homes and triggered a sandstorm that may have led to a fatal highway pileup.

Firefighters gained ground Monday on a wildfire along the northern edge of Los Angeles County that temporarily closed a major freeway and knocked out electricity to more than 4,000 homes, authorities said. The blaze had scorched more than 6 square miles of hillside and was 60% contained.